Flash Counter

War Barge

{3}: Target creature gains islandwalk until end of turn. When War Barge leaves the battlefield this turn, destroy that creature. A creature destroyed this way can't be regenerated. (A creature with islandwalk can't be blocked as long as defending player controls an Island.)

Remove Soul

Braingeyser

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

The Hive

{5}, {T}: Create a 1/1 colorless Insect artifact creature token with flying named Wasp. (It can't be blocked except by creatures with flying or reach.)

Merfolk Assassin

{T}: Destroy target creature with islandwalk.

Counterspell

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Anti-Magic Aura

Enchant creature
Enchanted creature can't be the target of spells and can't be enchanted by other Auras.

Psionic Blast

Psionic Blast deals 4 damage to any target and 2 damage to you.

Unsummon

Return target creature to its owner's hand.

Sol Ring

Island

Boomerang

Return target permanent to its owner's hand.

Control Magic

Enchant creature
You control enchanted creature.

Giant Tortoise

Giant Tortoise gets +0/+3 as long as it's untapped.

Ghost Ship

Strip Mine

{T}: Add {C}.
{T}, Sacrifice Strip Mine: Destroy target land.

Pirate Ship

Pirate Ship can't attack unless defending player controls an Island.
{T}: Pirate Ship deals 1 damage to any target.
When you control no Islands, sacrifice Pirate Ship.

Mahamoti Djinn

Flying (This creature can't be blocked except by creatures with flying or reach.)